The present invention relates to a device for providing communication, via a coupling means, between a first chamber and a second chamber, each sealed with respect to an external medium, for example the atmospheric air, and having to remain sealed with respect to said medium, notwithstanding the fact that they are brought into communication. As a consequence, the device for ensuring communication, while operating reversibly, is designed also to preserve the seal, with respect to this same external medium, of the passage made between the two chambers.
For the purposes of the present description, and the interpretation of the appended claims, the expressions xe2x80x9csealxe2x80x9d or xe2x80x9csealedxe2x80x9d should be understood as meaning characteristics whereby any one wall separating two mediums prevents or restricts any transfer through said wall of one or more reference substances, for example so-called contaminants.
The expressions xe2x80x9ccontaminantxe2x80x9d or xe2x80x9ccontaminationxe2x80x9d should be understood as meaning the characteristic whereby a substance has to remain excluded, or in a limited amount or concentration within a given medium. These are, for example, pathogens or pollutants, biological or otherwise, but also simple solid, liquid or gaseous particles which may be found in suspension in any fluid medium.
More specifically, but not exclusively, the present invention will be described hereinafter with reference to an application of the medical or biological type, requiring any contamination, including byparticles, originating from the external medium, to be avoided or limited. By way of example, as one, of the chambers is fixed, it consists for example of, a clean or sterile room, and the other chamber is removable, for example a use-once chamber, and contains one or more objects or a charge to be transferred, when the communication device is in the coupled position, through the passage thus made between the two chambers, namely from the removable chamber to the fixed chamber, for example to supply the latter with components or products required for the manufacture or production taking place in the clean room, or, conversely, to discharge waste or products from said room.
Various devices for allowing sealed communication between two chambers have already been proposed and are currently available on the market.
Thus, in accordance with document FR-A-2 721 289, to which reference is made as needed, such a device comprises:
on the same side as a first chamber, a first shut-off member comprising a first flange forming a seat for a first removable shutter element, with a sealing gasket between the seat and the shutter;
on the same side as a second chamber, a second shut-off member comprising a second flange forming a seat for a second removable shutter element, with a sealing gasket between the seat and the shutter;
means of sealed connection between the two flanges, determining a peripheral and continuous external critical line liable to be contaminated, and means for the sealed connection of the two shutter elements, determining a peripheral and continuous internal critical line liable to be contaminated, and contiguous with the external critical line;
one of the chambers being defined by the inside of a flexible and sealed bag, the border of the mouth of which is connected in a sealed way to the flange of the corresponding shut-off member.
As those skilled in the art well know, the expression xe2x80x9ccritical linexe2x80x9d is understood to mean a line with residual contamination from the external medium at the two chambers which are brought into communication. During or following coupling, this line is liable to come into contact with the atmosphere or fluid present in the passage made between the two chambers, or into contact with the product or products passing through said passage, and to contaminate them.
For a device as defined earlier, the present invention sets out to limit the possible contamination by the critical line or lines, without resorting to decontamination thereof prior to coupling, and without making the coupling means used any more complicated either as regards its structure or as regards its operation.
In accordance with the present invention, when the coupling means is in the uncoupled position, the flexible bag comprises, at the opposite end to its closed end, a band extending it continuously beyond the flange of the corresponding shut-off member, determining a closed and sealed, but openable envelope for protecting most of the corresponding shut-off member and comprising an annular strip connected to said corresponding flange for separating the inside of the bag from the inside of the protective envelope in a sealed way.
The term xe2x80x9ccontinuouslyxe2x80x9d should be understood as meaning the characteristic whereby the wall of the flexible bag is continuous with respect to the sealing against the external medium required, between, on the one hand, the body of the bag, forming its main part, and on the other hand, the band forming the protective envelope. This continuity is obtained in various ways, namely either by continuity of material, or by a weld or sealed join between the body of the bag and the band.
Thanks to the invention, the component of the critical line or lines which lies on the same side as the shut-off member of the flexible bag, is fully protected by the protective envelope prior to coupling with the other shut-off member.
The solution according to the present invention also makes it possible to provide a better long-term seal of the chamber corresponding to the inside of the flexible bag, because the sealing of said bag with respect to the flange of the corresponding shut-off member is no longer involved in the sealing of said bag against the external medium; all of this is, of course, true if it is considered that the inside of the protective envelope and the inside of the bag are at the same pressures, for example under vacuum. From this point of view, the flexible bag with its additional band, as defined earlier is, from the functional view point, merely one and the same closed sheath, for example welded at both ends, namely on each side of the corresponding shut-off member. Thanks to the invention, it is the flexible bag, and the flexible bag alone, which as mentioned earlier is in the form of a closed sheath, which provides the seal both of the corresponding shut-off member and of the charge throughout the period of storage of the use-once assembly defined hereinabove.
The solution according to the invention also makes it possible to limit even further any possible contamination resulting from the handling of the use-once assembly combining or including the shut-off member, designed to be coupled to the other shut-off member (on the same side as the fixed chamber for example) and the flexible and sealed bag.
This is what happens:
after opening, the protective envelope can be withdrawn by hand, without the hands coming into contact with the front face of the shutter of the corresponding shut-off member;
and the protective envelope assures the user that the shut-off member and, in particular, its shutter, have remained uncontaminated prior to the opening of the envelope.